Identification of Critical Links in Low Earth Orbit Satellite Networks Based on Temporal Connectivity

Low Earth orbit (LEO) satellite networks exhibit highly dynamic topologies, making it challenging to accurately identify critical inter-satellite links using conventional static graph methods. Existing approaches predominantly rely on delay or betweenness centrality as evaluation criteria and fail to account for temporal connectivity as a fundamental prerequisite for communication. This paper proposes the Evaluation of Temporal-Aware Path Connectivity (eTAPC), a method based on temporal connectivity for identifying critical links in LEO satellite networks. An event-driven slot partitioning strategy is adopted to construct a time-extended graph. Three complementary metrics are proposed, activity frequency, burstiness coefficient, and von Neumann entropy change, to characterize link importance from temporal coverage, fluctuation patterns, and topological bridging. These metrics are fused via the TOPSIS method with a predefined weight vector to produce a comprehensive ranking of link criticality. Experiments are conducted on real TLE data from both dense and sparse LEO constellations to validate the effectiveness of eTAPC. The results show that eTAPC outperforms existing methods on the dense Starlink constellation and achieves competitive performance on the sparse Iridium constellation. Overall, eTAPC provides a lightweight and effective solution for critical link identification in large LEO constellations, with low computational complexity.